FreeBSD/Linux Kernel Cross Reference
sys/dev/ic/lcdkp_subr.c

     /* $NetBSD: lcdkp_subr.c,v 1.7 2011/05/14 02:58:27 rmind Exp $ */
     
     /*
      * Copyright (c) 2002 Dennis I. Chernoivanov
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    /*
     * Subroutines for simple one-port keypad.
     */
    
    #include <sys/cdefs.h>
    __KERNEL_RCSID(0, "$NetBSD: lcdkp_subr.c,v 1.7 2011/05/14 02:58:27 rmind Exp $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/proc.h>
    #include <sys/conf.h>
    #include <sys/kernel.h>
    #include <sys/types.h>
    
    #include <machine/autoconf.h>
    #include <sys/intr.h>
    #include <sys/bus.h>
    
    #include <dev/ic/lcdkp_subr.h>
    
    #define HD_POLL_RATE    (hz / 10)
    
    static int    lcdkp_poll(struct lcdkp_chip *);
    static u_char lcdkp_scan(struct lcdkp_chip *, u_int8_t *);
    
    /*
     * Initialization.
     */
    void
    lcdkp_attach_subr(struct lcdkp_chip *sc)
    {
    
            sc->sc_flags = 0x0;
            mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE);
    }
    
    /*
     * Scan whether input is pending, don't block if not.
     */
    int
    lcdkp_scankey(struct lcdkp_chip *sc)
    {
            int ret;
    
            if ((sc->sc_knum == 0) || (sc->sc_kpad == NULL))
                    return 0;
    
            mutex_enter(&sc->sc_lock);
            if (!(sc->sc_flags & LCDKP_HAS_BUF)) {
                    u_int8_t b;
                    if (lcdkp_scan(sc, &b) != 0) {
                            sc->sc_buf = b;
                            sc->sc_flags |= LCDKP_HAS_BUF;
                    }
            }
            ret = (sc->sc_flags & LCDKP_HAS_BUF);
            mutex_exit(&sc->sc_lock);
    
            return ret;
    }
    
    /*
     * Read new key code, block if needed.
     */
    int
    lcdkp_readkey(struct lcdkp_chip *sc, u_int8_t *result)
    {
            int error;
    
            if ((sc->sc_knum == 0) || (sc->sc_kpad == NULL))
                   return EIO;
   
           mutex_enter(&sc->sc_lock);
           if ( (error = lcdkp_poll(sc)) == 0) {
                   *result = sc->sc_buf;
                   sc->sc_flags &= ~LCDKP_HAS_BUF;
           }
           mutex_exit(&sc->sc_lock);
   
           return 0;
   }
   
   /*
    * Scan the keypad and translate the input.
    */
   static u_char
   lcdkp_scan(struct lcdkp_chip *sc, u_int8_t *b)
   {
           u_int8_t i;
           u_int8_t c;
   
           c = lcdkp_dr_read(sc);
           for (i = 0; i < sc->sc_knum; i++) {
                   if (sc->sc_kpad[i].x_keycode == c) {
                           *b = sc->sc_kpad[i].x_outcode;
                           return 1;
                   }
           }
           return 0;
   }
   
   /*
    * Block until input is available.
    */
   static int
   lcdkp_poll(struct lcdkp_chip *sc)
   {
           int error;
           uint8_t b;
   
           KASSERT(mutex_owned(&sc->sc_lock));
   
           if (sc->sc_flags & LCDKP_HAS_BUF) {
                   return 0;
           }
           while (lcdkp_scan(sc, &b) == 0) {
                   error = mtsleep((void*)sc, PRIBIO | PCATCH, "kppoll",
                       HD_POLL_RATE, &sc->sc_lock);
                   if (error != EWOULDBLOCK) {
                           if (lcdkp_scan(sc, &b) != 0)
                                   break;
                           return EINTR;
                   }
           }
           sc->sc_buf = b;
           sc->sc_flags |= LCDKP_HAS_BUF;
           return 0;
   }

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